Superheater with adjustable counter radiation



March 3, 19,36. 0 w, ARMACOST 2,032,390

SUPERHEATER WITH ADJUSTABLE COUNTER RADIATION Filed Dec. 7, 1932 2 Sheets-Sheet 1 Wflbur H. Ar'mqcost 7 INVENTOR ATTORNEY March 3, 1936. w. H. ARMAcosT 2,032,390

SUPERHEATER WITH ADJUSTABLE COUNTER RADIATION Filed Dec. 7, 1952 2 Sheets-Sheet 2 Wflbur H. Armacost,

INVENTOR m. Zea-MA,

ATTORNEY UNITED STATES Patented Mar. 3, 1936 AT iii, if

SUPERHEATER WITH ADJUSTABLE COUNTER RADIATION Wilbur H. Armacost, New York, N. Y., assignor to Ihe Super-heater Company, New York, N. Y.

T ()FFIQE The present invention relates to superheater boilers and more particularly to arrangements whereby the steam may be given the desired final temperature.

H In installations in which a superheater receives its heat from the same furnace as a boiler, it is difficult to predict the final temperature of the steam at a given load on the boiler. The user, however, is always interested in knowing what such temperature will be not only because of its effect on the e fiiciency of the prime movers which may receive steam from the boiler, but also because excessive steam temperatures cause high ratesof depreciation in both prime movers and superheaters.

It is an object of the present invention to provide an arrangement whereby a desired final steam temperature at a given load may be obtained with a minimum of difliculty.

A further object of my invention is to provide a superheater adapted to absorb large amounts of heat per unit surface area without undue deterioration in use.

In accordance with my invention, the superheater units are so placed that they receive large amounts of heat per active unit area either by convection or radiation, or both, but are protected from over-heating by close proximity to a steam generating surface of the boiler, such surface limiting the maximum metal temperature of the superheater units by radiation from such units to the generating surface. Owing to the difficulty of predicting the amount of heat which will be absorbed by the superheater per unit active area due to varying factors of radiation and convection, the superheater surface necessary to produce a given final steam temperature is diflicult to estimate in advance, but I have found that it is possible to provide an ample amount of surface in the superheater and to regulate the final temperature of the steam for a given load on a given boiler by adjusting the amount of reradiation from the superheater units to the generating surface of the boiler.

In order that the invention, together with further objects and advantages thereof, may be easily and fully understood, I will now describe in detail, by way of example, two forms of superheater boilers in accordance with my invention and selected from a number of possible embodiments thereof, such description being taken with the accompanying drawings. In said drawings:

Fig. 1 is a side elevation, parts being broken away and parts being shown in section for purpose of illustration, of a fire tube boiler of special type having a superheater associated Fig. 3 is a detailed View on an enlarged scale of one of the turn buckles shown in Fig. 1.

Fig. 4 is a side elevation of a known type of water tube boiler and a superheater arranged within my invention.

Fig. 5 is a section on the line 5-5 of Fig. 4 5 looking in the direction of the arrows.

Referring to the arrangement illustrated in Figs. 1 and 2, it is a furnace chamber for a boiler it having a cylindrical shell portion I2 immediately above furnace l9. Boiler II also has a shell portion M of form elongated in cross section. The gases from furnace I 0 pass rearwardly thru a set of fire tubes :6, It in the lower part of portion i and then forwardly again thru fire tubes l8, it which extend thru portions l4 and I2. Boiler H is, of course, of known form.

In the arrangement shown, superheater units 25, 2B are placed in a group around the lower side of portion 92 so that they receive direct radiation from the combustion zone of the furnace l9 and also contact with gases therefrom.

However, my invention is not limited to heating the units by both radiation and convection. Evidently, units 26 absorb a large amount of heat per active unit area and, in order to prevent their becoming overheated, such active portions are placed close to the generating surface of the portion i2 and are substantially parallel thereto so that they may protect themselves against overheating by re-radiating heat to the generating surface. The units 20 therefore are of a semicircular or U shape and connect at their upper ends with suitable headers 22, 22, one of which is on each side of the boiler. Preferably headers 22 are placed above the horizontal plane thru the centre of boiler portion I2. While I do not limit myself to this, I find that it facilitates the insertion and removal of the units. It also facilitates'adjustment of the headers and units to produce a desired final steam temperature. In order that the headers 22 and thereby the units 26 may be adjusted to produce a desired final steam temperature, headers 22 are shown as supported by rods 24, 24 which pass above the shell portion i2 and transfer the weight of the superheaters to such portion. As shown, rods 24 are arranged in pairs which pass thru turnbuckles 26 which have nuts 28, 23 threaded on the ends of the rods 2% whereby the effective lengths of such rods may be varied to vary the position of myself to a single layer arrangement, I find that such arrangement accentuates the effect, on the final steam temperature, of an adjustment of the a position of units 20 with respect to portion-I2.

Referring more particularly to Figs. 4 and 5,

I have shown therein a known type of -water tube boiler having a generating bank composed of water tubes 32, 32 and also ardrum 3.4. .As appears more clearly in Fig. 5, tubes 32 form a bank which is rectangular in cross section. The j-lowest row of tubes32 is exposed,.at.-least impart, to radiant ,heat and gases from the furnace .,chamber HlA. The'superheater shown in Figs. 4 and 5 is composed of superheater units 36,36 themost active parts of which extend beneath and parallel to the .plane of the lowermostrow of .the tubes .32 and transversely thereof, pref- :erably in -a position to receive heat both by radiation and convection from the furnace ill-A. .However, I do not limit myself :to this. vAs shown, the units 3Bare.of right-angled U-form and extend upwardly along the bank formed by tubes v32 .to connect with headers 38, 38 which lie one .on each side of the drum l0. While I do not limit myself to the use of U-shaped units in the type .of boiler illustrated in Figs. 4 and 5, the arrange- .ment illustrated is advantageous in that it is readily applied to existing boilers. Moreover, it -does not require any'change in the boiler design to accommodate the superheater.

.It will be seen that the units 36 are placed .sufliciently close to the lowermost row of tubes .32 so that the units .36 may protect themselves from overheating by re-radiation of the tubes 32. ,;In or-der to permit adjusting the final steam temperature from such an arrangement, I have shown in Figs. 4 and 5 a supporting means for the headers 38 comprising angle irons 40, 40 fixed tothe sides of the headers and resting onstacks of ;plates 42, .42 which are supported in turn by the roof of the boiler. It is .evident that the height of the headers 38 and thereby the position of the units 36 with respect to the lowest .row of tubes 32 may be varied by increasing or decreasing the thickness of the stacks of plates 42 beneath the angle irons 40. In order not to disturb the piping leading to and from the headersby such an adjustment, flange joints 44,44 .may be placed in-the piping close to the headers .38 and the length of the piping adjusted to the position of the headers 38 by increasing or de- ;creasing. the'thickness of a fiat ring-shaped filler -member or Dutchman 46 in each of such joints. Such Dutchmen 46 being of-the same outside diameter and apertured the same as flanges can be readily withdrawn from between 'flanges'M and another one placed between such .flanges whenever adjustment of the position of the headers 38 has made it necessary to do so. Whenever'the width of the generating bank of .sucha boiler as that shown in Figs. 4 and 5 is row of tubes 32. In the arrangement shown in Figs. 4 and 5, I have employed a heavy plate 48 extending beneath the units 36 near their centers and supported from tubes 32 by means of U-bolts 50, 50 whose effective length may be varied by means of nuts 52, 52. Although both arrangements illustrated in the drawings have the superheater surrounding a portion of the boiler, I do not limit myself to such feature but. may employ the invention in connection with a superheater which is surrounded by the boiler surface.

Neither do I limit myself to the use of superheaters of themultiple unit type.

In both the arrangements illustrated herein, the superheater units are grouped in a zone of gas fiow'in which the temperature of the gases "striking the units changes relatively slightly throughout such zone, the gases in contact with boiler surface in such zone being above the units and the units being open to contact with fresh uncooled furnace gases frombelow. The; entire surface of .the superheater is therefore subject .to .the boiler surface as above described.

.It will be seen that the-embodimentof theinvention illustrated in Figs. 1 and 29nd .theem- Y bodiment of the invention illustrated .in Figs. 4

and Beach have piping connections extending in the same.-.direction that it is desired to adjust the headers of thesuperheater, so that such adjustment does not vary the .angle between the header and the piping whereby .the adjustment maybe made withmaximum convenience.

While I have illustratedin the drawings aparticular vformof superheater boiler comprising a cylindrical shell portion and units such -as 23. extending from .one side to .the other beneath said shell..and substantially parallel thereto, .1

.do not claim such combination herein since I have already claimed it in my prior .Patent .No. 1,903,970,.datedApril 18,.1933. ,In .fact,.Figs. 1,

.2, and 3 of this application are identical with certainfigures in mysaid prior application.

Further, while the arrangement illustrated in Figs. .4 and 5 of the drawings include superheater units adapted to permit varying the final steam temperature by adjusting the units .to change their effective area by changing the distance between the cross-pieces or bridge pieces of the right-angled U-shaped units, .1 have not .claimed such way of varying the final steam temperatures herein, because the units shown in, Figs.

1 .and2 possesssuch .utility to only a minor degree and I have claimed it in my application Serial No. 653,254, filed January 24, .1933, for superheater with adjustable surface.

' What I claim is:

1. The combination with a boiler having a horizontal cylindrical shell portion, of .means for passing :heating gases along the lowerouter surface of said portion, a superheater having tubes running beneath said portion from side to side thereof and each substantially parallel to its outer surface, means whereby the distance be- .tween the tubes of said superheater and .the surface of said shell portion may be adjusted,

and pipe connections between said boiler and said superheater having a readily replaceable portion to permit the commercial utilization of said adjusting means, said pipe connections having an arrangement such that the angle between said superheater and said pipe connections is the same in different positions of the superheater.

2. The combination with a boiler having a horizontal cylindrical shell portion, of means for heating at least a part of the lower outer surface of said portion, a superheater having tubes running beneath said portion from side to side thereof within the zone afiected by said means, and each substantially parallel to its outer surface, headers for the superheater, one on each side of the boiler, supporting means for the superheater comprising rods connected to said headers and running across the top of the boiler, and means for adjusting the effective lengths of said rods to determine the position of the tubes of the superheater with respect to the boiler surface.

3. The combination with a horizontal cylindrical boiler portion, of means of passing heating gases along the lower outer surface of said portion, a superheater having tubes arranged in a single layer running beneath said portion from side to side thereof and substantially parallel to the outer surface of the portion, means whereby the distance between the tubes of the superheater and the outer surface of said portion may be adjusted, and pipe connections between said boiler portion and said superheater having a readily replaceable portion whereby said adjusting means may be commercially utilized, said superheater and pipe connections having an arrangement such that the angle between them is the same in different positions of the superheater.

4. The combination as set forth in claim 3 and in which the superheater has headers one on each side of the boiler and the means whereby the distances between the tubes of the superheater and the boiler may be adjusted includes rods extending across the top of the boiler and turnbuckles for adjusting the effective lengths of said rods.

5. The combination with a furnace of a boiler so associated therewith as to have a steam generating portion directly facing the combustion zone in said furnace, a pair of horizontal headers at a level above said furnace and on each side thereof, superheater units having their upper ends substantially vertical and connected to the bottom faces of said headers, the central portions of said units looping around said generating portion intermediate said portion and said furnace so as to receive radiation from said furnace, supporting means for said headers adapted for ready vertical adjustment to thereby vary the distance between said units and said generating portion to thereby vary the final temperature of steam delivered by said units, connections between said boiler and one of said headers whereby steam may be passed through said units, and a joint in the connections between the boiler and header comprising outside flanges and a ring-like intermediate member of substantially the same diameter as said flanges whereby the adjustment in vertical height of the header may be readily compensated for by removal of such intermediate member and substitution therefor of another of different thickness.

6. The combination of a water tube boiler having a main bank of tubes that is substantially rectangular in cross section, U-shaped superheater units extending transversely beneath the lower edge of said bank and in position to radiate excessive heat thereto, means whereby the position of said units with relation to said bank may be adjusted to vary the final steam temperature, and means for supporting the center portions of the units from the tubes in the generating bank.

'7. The method of regulating the final temperature of steam delivered by a superheater associated with a boiler which comprises; positioning the heat absorbing portions of the super heater units in a high temperature zone in the boiler sufiiciently close to generating portions of the boiler as to radiate substantial amounts of heat to said generating portions, and changing the distance of said portions of said units from the surfaces of said generating portions within the zone of good radiation for varying the amount of heat re-radiated to the latter from said units in order to alter the final steam temperature.

WILBUR H. ARMACOST. 

